Optimization of the safety factor profile for high noninductive current fraction discharges in DIII-D
Abstract not provided
70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
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Results for “FRACTIONATING”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Measurements of Branching Fractions and CP Asymmetries and Studies of Angular Distributions for B to phi phi K Decays
We present branching fraction and CP asymmetry measurements as well as angular studies of B {yields} {phi}{phi}K decays using 464 x 10{sup 6} B{bar B} events collected by the BABAR experiment. The branching fractions are measured in the {phi}{phi} invariant mass range below the {eta}{sub c} resonance (m{sub {phi}{phi}} < 2.85 GeV). We find {Beta}(B{sup +} {yields} {phi}{phi}K{sup +}) = (5.6 {+-} 0.5 {+-} 0.3) x 10{sup -6} and {Beta}(B{sup 0} {yields} {phi}{phi}K{sup 0}) = (4.5 {+-} 0.8 {+-} 0.3) x 10{sup -6}, where the first uncertaintiy is statistical and the second systematic. The measured direct CP asymmetries for the B{sup {+-}} decays are A{sub CP} = -0.10 {+-} 0.08 {+-} 0.02 below the {eta}{sub c} threshold (m{sub {phi}{phi}} < 2.85 GeV) and A{sub CP} = 0.09 {+-} 0.10 {+-} 0.02 in the {eta}{sub c} resonance region (m{sub {phi}{phi}} in [2.94,3.02] GeV). Angular distributions are consistent with J{sub P} = 0{sup -} in the {eta}{sub c} resonance region and favor J{sup P} = 0{sup +} below the {eta}{sub c} resonance.
79 ASTRONOMY AND ASTROPHYSICS↗
Invariant-mass and fractional-energy dependence of inclusive production of dihadrons in e + e - annihilation at s = 10.58 GeV
The inclusive cross sections for dihadrons of charged pions and kaons ( e + e - → h h X ) in electron-positron annihilation are observed and reported on. They are obtained as a function of the total fractional energy and invariant mass for any di-hadron combination in the same hemisphere as defined by the thrust event-shape variable and its axis. Since same-hemisphere dihadrons can be assumed to originate predominantly from the same initial parton, di-hadron fragmentation functions are probed. Moreove, these di-hadron fragmentation functions are needed as an unpolarized baseline in order to quantitatively understand related spin-dependent measurements in other processes and to apply them to the extraction of quark transversity distribution functions in the nucleon. The di-hadron cross sections are obtained from a 655 fb - 1 data sample collected at or near the Υ ( 4 S ) resonance with the Belle detector at the KEKB asymmetric-energy e + e - collider.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Search for C P Violation and Measurement of the Branching Fraction in the Decay D 0 → K S 0 K S 0
In this work we study the decay D 0 → K S 0 K S 0 using 921 fb - 1 of data collected at or near the Υ ( 4 S ) and Υ ( 5 S ) resonances with the Belle detector at the KEKB asymmetric energy e + e - collider. The measured time-integrated C P asymmetry is A C P ( D 0 → K S 0 K S 0 ) = ( - 0.02 ± 1.53 ± 0.02 ± 0.17 ) % , and the branching fraction is B ( D 0 → K S 0 K S 0 ) = ( 1.321 ± 0.023 ± 0.036 ± 0.044 ) × 10 - 4 , where the first uncertainty is statistical, the second is systematic, and the third is due to the normalization mode ( D 0 → K S 0 π 0 ). These results are furthermore more precise than previous measurements available for this mode. The A C P measurement is consistent with the standard model expectation.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Improved Understanding of Airborne Release Fraction and Respirable Fraction from Postulated Free-Fall Spill in DOE Nuclear Facilities (Annual Project Summary Report for NSRD-38)
The two-year experimental project has been completed to update the Airborne Release and Respirable Fraction (ARF and RF) estimates from the free-fall spills of liquid waste simulants. The objectives of the project at the Savannah River National Laboratory (SRNL) are to: (1) establish a technically defensible bounding approach for a reasonably conservative limit to the fall height used in the Ballinger correlation for the ARF, such that spill heights for near-water density liquid solutions above a critical height result in the same value of the ARF; and (2) provide a revised technical basis and data to support the ARF and RF correlation for free-fall liquid spills of heights from 1 to 10 meters. After peer review, these data and associated correlation will be available for consideration in a revision to DOE-HDBK-3010, Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities.
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Data for "1H NMR quantification of aromatic monomers from reductive catalytic fractionation"
Data here corresponds to the data presented in the academic publication titled "1H NMR quantification of aromatic monomers from reductive catalytic fractionation" set to be published in ACS Sustainable Chemistry and Engineering. Data was gathered at the National Renewable Energy Laboratory From 2022-2025.
09 BIOMASS FUELS↗
Measurement of the production fraction times branching fraction $\boldsymbol{ f(b\to\Lambda_{b})\cdot \mathcal{B}(\Lambda_{b}\to J/\psi \Lambda)}$
The {Lambda}{sub b}(udb) baryon is observed in the decay {Lambda}{sub b} {yields} J/{psi}{Lambda} using 6.1 fb{sup -1} of p{bar p} collisions collected with the D0 detector at {radical}s = 1.96 TeV. The production fraction multiplied by the branching fraction for this decay relative to that for the decay B{sup 0} {yields} J/{psi}K{sub s}{sup 0} is measured to be 0.345 {+-} 0.034 (stat.) {+-} 0.033 (syst.) {+-} 0.003 (PDG). Using the world average value of f(b {yields} B{sup 0}) {center_dot} {Beta}(B{sup 0} {yields} J/{psi}K{sub s}{sup 0}) = (1.74 {+-} 0.08) x 10{sup -5}, they obtain f(b {yields} {Lambda}{sub b}) {center_dot} {Beta}({Lambda}{sub b} {yields} J/{psi}{Lambda}) = (6.01 {+-} 0.60 (stat.) {+-} 0.58 (syst.) {+-} 0.28 (PDG)) x 10{sup -5}. This measurement represents an improvement in precision by about a factor of three with respect to the current world average.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Fractional occupation numbers and self-interaction correction-scaling methods with the Fermi-Löwdin orbital self-interaction correction approach
In this work, we present a new assessment of the Fermi-Löwdin orbital self-interaction correction (FLO-SIC) approach with an emphasis on its performance for predicting energies as a function of fractional occupation numbers (FONs) for various multielectron systems. Our approach is implemented in the massively parallelized NWChem quantum chemistry software package and has been benchmarked on the prediction of total energies, atomization energies, and ionization potentials of small molecules and relatively large aromatic systems. Within our study, we also derive an alternate expression for the FLO-SIC energy gradient expressed in terms of gradients of the Fermi-orbital eigenvalues and revisit how the FLO-SIC methodology can be seen as a constrained unitary transformation of the canonical Kohn–Sham orbitals. Finally, we conclude with calculations of energies as a function of FONs using various SIC-scaling methods to test the limits of the FLO-SIC formalism on a variety of multielectron systems. We find that these relatively simple scaling methods do improve the prediction of total energies of atomic systems as well as enhance the accuracy of energies as a function of FONs for other multielectron chemical species.
fractional occupation number↗
In-plane electric fields and the 𝜈 = $\frac{5}{2}$ fractional quantum Hall effect in a disk geometry
The 𝜈 = $\frac{5}{2}$ fractional quantum Hall effect is of experimental and theoretical interest due to the possible non-Abelian statistics of the excitations in the electron liquid. A small voltage difference across a sample applied in experiments to probe the system is often ignored in theoretical studies due to the Galilean invariance in the thermodynamic limit. No experimental sample, however, is Galilean invariant. In this Rapid Communication, we explore the effects of the probe electric fields in a disk geometry with finite thickness. We find that weak probe fields enhance the Moore-Read Pfaffian state, but sufficiently strong electric fields destroy the incompressible state. In a disk geometry, the behavior of the system depends on the polarity of the applied radial field, which can potentially be observed in experiments using a Corbino disk configuration. Finally, our simulation also shows that the application of such a field enhances the coherence length of quasiholes propagating through the edge channels.
exact diagonalization↗
Anomalous density and elastic properties of basalt at high pressure: Reevaluating of the effect of melt fraction on seismic velocity in the Earth's crust and upper mantle
Independent measurements of the volumetric and elastic properties of Columbia River basalt glass were made up to 5.5 GPa by high-pressure X-ray microtomography and GHz-ultrasonic interferometry, respectively. The Columbia River basalt displays P and S wave velocity minima at 4.5 and 5 GPa, respectively, violating Birch’s law. These data constrain the pressure dependence of the density and elastic moduli at high pressure, which cannot be modeled through usual equations of state nor determined by stepwise integrating the bulk sound velocity as is common practice. We propose a systematic variation in compression behavior of silicate glasses that is dependent on the degree of polymerization and arises from the flexibility of the aluminosilicate network. Likewise, this behavior likely persists into the liquid state for basaltic melts resulting in weak pressure dependence for P wave velocities perhaps to depths of the transition zone. By modeling the effect of partial melt on P wave velocity reductions it is suggested that melt fraction determined by seismic velocity variations may be significantly overestimated in the crust and upper mantle.
58 GEOSCIENCES↗
Reactive oxygen species alter chemical composition and adsorptive fractionation of soil organic matter
Reactive oxygen species (ROS), formed during redox fluctuations in iron-rich soils, have been known to stimulate lignin degradation, although not much is known about how they alter soil organic matter (SOM) composition and interaction with mineral surfaces. We conducted a laboratory experiment to see how ROS altered SOM composition and adsorptive fractionation onto Fe-mineral surfaces. We reacted water extracts of SOM with ·OH, produced by the Fenton reaction, and then conducted a sorption experiment of the extracts with goethite to analyze the amount and quality of SOM adsorbed. The Fenton reaction preferentially consumed low-O, mostly aromatic molecules, and new high-O molecules were detected post-Fenton, nearly half of which were carbohydrate-like. Although the amount of C adsorbed did not change after oxidation, the post-Fenton adsorbed molecules were more oxidized. Pre-Fenton adsorption was dominated by aromatic molecules (90%), but post-Fenton, the adsorbed molecules were 75% aromatic and 25% carbohydrate-like. We show that the ·OH radical oxidized SOM and shifted patterns of adsorption to a more oxidized pool. Because adsorption to minerals is thought to stabilize SOM, our results suggest that ROS may alter the availability and stabilization patterns of SOM.
Patel, Kaizad F.↗
Analysis of Organic Anionic Surfactants in Fine and Coarse Fractions of Freshly Emitted Sea Spray Aerosol
Not Available
Cochran, Richard E.↗
Effective Biomass Fractionation through Oxygen-Enhanced Alkaline–Oxidative Pretreatment
The high recalcitrance of plant cell walls is an obstacle for effective chemical or biological conversion into renewable chemicals and transportation fuels. Here, we investigated the utilization of both oxygen (O 2 ) and hydrogen peroxide (H 2 O 2 ) as co-oxidants during alkaline-oxidative pretreatment to improve biomass fractionation and increase enzymatic digestibility. The oxidative pretreatment of hybrid poplar was studied over a variety of conditions. Employing O 2 in addition to H 2 O 2 as a co-oxidant during the two-stage alkaline pre-extraction/copper-catalyzed alkaline hydrogen peroxide (Cu-AHP) pretreatment process resulted in a substantial improvement in delignification relative to using H 2 O 2 alone during the second-stage Cu-AHP pretreatment, leading to high overall sugar yields even at H 2 O 2 loadings as low as 2% (w/w of original biomass). The presence of H 2 O 2 , however, was both critical and synergistic. Performing analogous reactions in the absence of H 2 O 2 resulted in approximately 25% less delignification and a 30% decrease in sugar yields. Here, the lignin isolated from this dual oxidant second stage had high aliphatic hydroxyl group content and reactivity to isocyanate, indicating that it is a promising substrate for the production of polyurethanes. To test the suitability of the isolated lignin as a source of aromatic monomers, the lignin was subjected to a sequential Bobbitt’s salt oxidation followed by formic-acid catalyzed depolymerization process. Monomer yields of approximately 17% (w/w) were obtained, and the difference in yields was not significant between lignin isolated from our Cu-AHP process with and without O 2 as a co-oxidant. Thus, the addition of O 2 did not lead to significant lignin crosslinking, a result consistent with the two-dimensional heteronuclear single-quantum coherence (2D HSQC) NMR spectra of the isolated lignin.
09 BIOMASS FUELS↗
Design and Validation of a High-Throughput Reductive Catalytic Fractionation Method
Reductive catalytic fractionation (RCF) is a promising method to extract and depolymerize lignin from biomass, and bench-scale studies have enabled considerable progress in the past decade. RCF experiments are typically conducted in pressurized batch reactors with volumes ranging between 50 and 1000 mL, limiting the throughput of these experiments to one to six reactions per day for an individual researcher. Here, we report a high-throughput RCF (HTP-RCF) method in which batch RCF reactions are conducted in 1 mL wells machined directly into Hastelloy reactor plates. The plate reactors can seal high pressures produced by organic solvents by vertically stacking multiple reactor plates, leading to a compact and modular system capable of performing 240 reactions per experiment. Using this setup, we screened solvent mixtures and catalyst loadings for hydrogen-free RCF using 50 mg poplar and 0.5 mL reaction solvent. The system of 1:1 isopropanol/methanol showed optimal monomer yields and selectivity to 4-propyl substituted monomers, and validation reactions using 75 mL batch reactors produced identical monomer yields. To accommodate the low material loadings, we then developed a workup procedure for parallel filtration, washing, and drying of samples and a 1H nuclear magnetic resonance spectroscopy method to measure the RCF oil yield without performing liquid-liquid extraction. As a demonstration of this experimental pipeline, 50 unique switchgrass samples were screened in RCF reactions in the HTP-RCF system, revealing a wide range of monomer yields (21-36%), S/G ratios (0.41-0.93), and oil yields (40-75%). These results were successfully validated by repeating RCF reactions in 75 mL batch reactors for a subset of samples. We anticipate that this approach can be used to rapidly screen substrates, catalysts, and reaction conditions in high-pressure batch reactions with higher throughput than standard batch reactors.
BIOMASS FUELS,INORGANIC, ORGANIC, PHYSICAL, AND AN↗
Methanogenesis in oxygenated soils is a substantial fraction of wetland methane emissions
The current paradigm, widely incorporated in soil biogeochemical models, is that microbial methanogenesis can only occur in anoxic habitats. In contrast, here we show clear geochemical and biological evidence for methane production in well-oxygenated soils of a freshwater wetland. A comparison of oxic to anoxic soils reveal up to ten times greater methane production and nine times more methanogenesis activity in oxygenated soils. Metagenomic and metatranscriptomic sequencing recover the first near-complete genomes for a novel methanogen species, and show acetoclastic production from this organism was the dominant methanogenesis pathway in oxygenated soils. This organism, Candidatus Methanothrix paradoxum, is prevalent across methane emitting ecosystems, suggesting a global significance. Moreover, in this wetland, we estimate that up to 80% of methane fluxes could be attributed to methanogenesis in oxygenated soils. Together, our findings challenge a widely held assumption about methanogenesis, with significant ramifications for global methane estimates and Earth system modeling.
54 ENVIRONMENTAL SCIENCES↗